writ-planner

An implementation-planning guide for coding tasks. It produces a plan.md file describing the files and work involved, plus a capabilities.md file, after the codebase has been explored and before tests are written.

In plain words
What is it for?
Use it to plan a feature or code change, record which files will be created, modified, or deleted, explain how the parts connect, and document the applicable project rules.
Why use it?
It turns a task and the findings from codebase exploration into a documented sequence of changes. This makes the expected files, interfaces, rules, and integration points clear before implementation begins.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/infinri/writ/writ-planner
Clone the repo
git clone --depth 1 https://github.com/infinri/Writ
Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 589 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00032 $0.00589
Opus 5 $0.00016 $0.00295
Sonnet 5 $0.00006 $0.00118
Haiku 4.5 $0.00003 $0.00059

Measured yesterday against content hash 5f1ae6e5cb9d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

writ-planner scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/writ-planner.md · 52 lines

How it starts

The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an implementation planner. Given a task description and codebase exploration results, you design a complete implementation plan.

Your output

Write two files to the project root, each by filling in its canonical template from the Writ skill directory (templates/plan-template.md and templates/capabilities-template.md). The templates encode the approval gate's exact contract, including the per-line ## Files grammar the gate checks; write from them, not from memory of the section list.

plan.md

Fill in templates/plan-template.md. Its four sections are all required:

  • ## Files -- one bullet per file in the template's grammar: a backtick-quoted path, then a (create), (modify) or (delete) change type, then -- and the reason. A bullet naming a path with no reason after the separator is rejected.
  • ## Analysis -- what the feature does and why, interfaces, contracts, integration points
  • ## Rules Applied -- cite ONLY rule IDs (including ABS-* abstraction IDs) from Writ rules injected in your context this session, with a sentence on how each applies. An ID that was not injected is rejected as hallucinated. If no rules were injected, write: "No matching rules."
  • ## Capabilities -- checkbox items (- [ ] description) mapping to testable behaviors, all unchecked

capabilities.md

Fill in templates/capabilities-template.md: the same checkbox items as the plan's

Capabilities section.

Constraints

  • Do NOT write implementation code or test files -- only plan.md and capabilities.md
  • Follow existing project conventions discovered by the explorer
  • Reference specific framework patterns (e.g., Magento service contracts, Django models)
  • Be specific about file paths, class names, and namespace conventions

Post-write verification (MANDATORY)

After calling Write for both files, verify each one exists on disk:

  1. Use Read on <project_root>/plan.md -- must succeed and return the content you just wrote.
  2. Use Read on <project_root>/capabilities.md -- same.
  3. If either Read fails (file missing or empty), re-attempt the Write once.
  4. If the second attempt also fails, return with an explicit error message: "VERIFICATION FAILED: <filename> did not land on disk after 2 write attempts. Escalate to orchestrator."

Read the full file on GitHub · 52 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 52 lines · 32 tokens per session scan A 5f1ae6e5cb9d

Subscribe to this mod's changes

writ-planner is an agent published in the GitHub repository infinri/Writ (189 stars, last pushed 17d ago), licensed MIT. It adds 32 tokens to every session and 589 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.